1. Field of the Invention
The invention relates to a lift car with a brake device which is arranged in the region of the lift car for holding and braking the lift car, a lift system having a lift car of this type and to a method for holding and braking a lift car of this type.
2. Description of the Related Art
A lift system serves essentially for the vertical transport of goods or persons. The lift system contains, for this purpose, one or more lift cars for receiving the goods or persons, said lift car being movable along a guide track. As a rule, the lift system is installed in a building, and the lift car transports goods or persons from and to various stories of this building. In a conventional version, the lift system is installed in a lift well of the building, and it contains, in addition to the lift car, carrying means which connect the lift car to a counterweight. The lift car is moved by means of a drive which acts selectively on the carrying means, directly on the lift car or on the counterweight. The guide track for guiding the lift car is often a guide rail which is fastened to the building or in the lift well. Lift systems of this type are equipped with brake systems which can hold the lift car at a story stop and/or brake and hold the lift car in the event of a fault. The brake system cooperates for braking purposes with a brake track which is usually integrated into the guide rail. Lift systems of this type can, of course, also be arranged outside the building, in which case the guide rails may be part of a scaffold. Conventional catching devices are not designed to be capable of holding the lift car in a holding position, for example for loading the lift car, since they can be put into operation again only by a service engineer.
EP0648703 discloses a brake device for a lift car, which brake device is arranged in the region of the lift car and can be used for holding and braking. The brake device shown there contains in this case a fluidic brake unit which can cooperate with a brake rail, an actuation device which can actuate the brake unit and a connection means which connects the brake unit force-actively to the brake unit. The actuation device is a hydraulic pressure station which is connected via hydraulic connection means to individual brake units and thereby actuates the hydraulic brake unit force-actively. Force-actively in this context means that a hydraulic pressure generated in the actuation device actively defines a pressure force, resulting in the brake unit, of brake linings against the brake rail. This solution uses hydraulic pressure generators. This is costly and complicated in terms of procurement and maintenance. Components of this type, moreover, are noise-intensive, and safety precautions have to be taken in order to limit the effects of leakages.
Moreover, nowadays, car brake devices are increasingly used in order, for example, to retain a lift car at a story stop during the loading operation or to correct a faulty behavior of the lift car quickly and smoothly.